Speculative revert by sheriff

ui/compositor/layer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/compositor/layer.h"
 
 #include <algorithm>
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
@@ skipping 733 matching lines @@
     SkCanvas* sk_canvas,
     const gfx::Rect& clip,
     ContentLayerClient::PaintingControlSetting painting_control) {
   TRACE_EVENT1("ui", "Layer::PaintContents", "name", name_);
   scoped_ptr<gfx::Canvas> canvas(gfx::Canvas::CreateCanvasWithoutScaling(
       sk_canvas, device_scale_factor_));
   if (delegate_)
     delegate_->OnPaintLayer(PaintContext(canvas.get(), clip));
 }
 
-void Layer::PaintContentsToDisplayList(
-    cc::DisplayItemList* display_list,
+scoped_refptr<cc::DisplayItemList> Layer::PaintContentsToDisplayList(
     const gfx::Rect& clip,
     ContentLayerClient::PaintingControlSetting painting_control) {
   TRACE_EVENT1("ui", "Layer::PaintContentsToDisplayList", "name", name_);
+  scoped_refptr<cc::DisplayItemList> list = cc::DisplayItemList::Create();
   if (delegate_) {
     // TODO(danakj): Save the invalidation on the layer and pass that down
     // instead of the |clip| here. That will break everything until View
     // early-outs emit cached display items instead of nothing.
     gfx::Rect invalidation = clip;
     DCHECK(clip.Contains(invalidation));
     delegate_->OnPaintLayer(
-        PaintContext(display_list, device_scale_factor_, clip, invalidation));
+        PaintContext(list.get(), device_scale_factor_, clip, invalidation));
   }
+  return list;
 }
 
 bool Layer::FillsBoundsCompletely() const { return fills_bounds_completely_; }
 
 bool Layer::PrepareTextureMailbox(
     cc::TextureMailbox* mailbox,
     scoped_ptr<cc::SingleReleaseCallback>* release_callback,
     bool use_shared_memory) {
   if (!mailbox_release_callback_)
     return false;
@@ skipping 313 matching lines @@
       children_.end(),
       std::bind2nd(std::mem_fun(&Layer::RemoveAnimatorsInTreeFromCollection),
                    collection));
 }
 
 bool Layer::IsAnimating() const {
   return animator_.get() && animator_->is_animating();
 }
 
 }  // namespace ui